Trencher



J. A. SMITH Sept. 14, 1943.

TRENCHER Filed March 28, 1941 5 Sheets-Sheet 2 INVENTOR Joseph A Smith ATTORNEYS J. A. SMITH TRENCHER Filed March 28, 1941 5 Sheets-Sheet 3 INVENTOR Joseph A. Smith ATTORNEYS Sept. 14, 1943.

. 7 Ma m Patented Sept. 14, 1943 TRENCHER Joseph A. Smith, Marietta, Ohio Application March 28, 1941, Serial No. 385,712

12 Claims.

This invention relates to trenching apparatus, and more particularly to a trencher for excavating or stripping pipe lines and the like. It frequently becomes necessary in oil field operations and related work to uncover or expose a buried pipe. Machines for performing this operation are well known and the present invention is concerned with improvements in pipe strippers of the rotary wheel type. Such improvements include means engagable with the pipe for indicating the direction or course of the pipe before the pipe normally would be visible to the operator. The indicating means also cooperates with the excavator wheel to remove the earth from the sides and top of the pipe. The invention also provides means for mounting the excavator wheel boom for horizontal and vertical pivotal or swinging movement relative to the tractor. The use of the invention enables the pipe to be uncovered by a smaller crew than heretofore required for similar work and permits faster operation of the apparatus without preliminary location of the course to be followed by the uncovering apparatus.

In addition to the objects and advantages mentioned above, the present invention aims to provide numerous improvements in structural details of the apparatus, particularly with reference to the manner of mounting the boom on the traction machine. Other objects and advantages will become apparent from the following detailed description of a suitable embodiment of the invention made in connection with the accompanying drawings, in which:

Figure l is a side elevational view of a pipe stripping trencher shown in operative position above a buried pipe line;

Fig. 2 is a fragmentary elevational view showing-the excavating and direction indicating plow in operative association vwith a section of pipe;

Fig. 3 is a sectional detail taken substantially on the line 3--3 of Fig. 2 and enlarged with respect thereto, showing the connection between the plow and the vertical rod of the direction indicator;

Fig. 4 is a plan view of the plow and boom guide, partially in section and with parts removed, taken substantially on the line 4--4 of Fig. 2;

Fig. 5 is a front elevational view of the plow, partially in section and with parts removed, taken substantially on the line 5-5 of Fig. 2 and enlarged with respect thereto;

Fig. 6 is a sectional detail taken substantially on the line 66 of Fig. 2 and enlarged with respect thereto;

Fig. '7 is a sectional detail taken substantially on the line 1-1 of Fig. 5;

Fig. 8 is a fragmentary plan view, partially in section and with parts broken away, showing the absorber or yieldable connection for the boom' supporting line.

Referring to the drawings by numerals of reference which indicate like parts throughout the several views, the present invention is shown embodied in apparatus which includes a trencher that may be of conventional design and construction except in so far as it is modified by the structure described herein. The trencher comprises a vehicle or tractor having a frame I, engine 2, and caterpillar crawlers 3, the latter being driven from the engine 2 by a chain 4. Suitable control mechanism for starting, stopping and steering is provided. The tractor frame I includes spaced uprights 5 which support an excavator wheel frame or boom 6 in a manner to be later described. Adjacent the outer end of spaced horizontal side members I and 8 of the boom are cross members 9 which are secured to spaced vertical supporting members II! that extend downwardly and at their lower ends carry between them a shaft l I for the boom supporting and guiding wheel l2. This wheel has a surface or surfaces l5 for engaging the top of pipe IE to be excavated over a relatively short circumferential distance so as to reduce the friction incident to drawing the wheel along the pipe, and in such manner as to distribute the weight of the digging assembly to secure the greatest resistance of the pipe being excavated against crushing or distortion. Circular end members or plates I! on the wheel H. are normally held by the engagement between the angularly disposed curved surf-aces l5 away from the sides of the pipe IE to provide clearance l8. Under conditions of extreme sideways or lateral pressure exerted against the excavator wheel or boom the wheel 12 may shift axially relative to the pipe [6 so that one of the plates l'l may engage one side of the pipe, serving to prevent the wheel from riding completely off the pipe. The space between the wheel plates I1 and the sides of the pipe also provides clearance for couplings and welds of the pipe joints. Horizontal and angular braces l9 and 20 are provided to hold the upright supporting members In in rigid relation to the boom members 1 and 8.

Plate members 2! are secured, as by welding,

to the lower ends of the uprights l and extend forwardly therefrom in parallel relation to one another. Between the forward ends of the plates 2| is disposed a journal member or block 22 which rotatably receives a short shaft 23 mounted therein for pivotal or turning movement about a vertical axis. A pivot block 24 is secured on a reduced diameter portion of the vertical shaft 23 and is formed with an upwardly extending circular boss 25 that is received within a recess 26 formed in the bottom of the journal member 22. Studs 21 are secured in opposite sides of the pivot element 24 in axially aligned relation to one another and receive the ends of spaced side members..28 of a plow structure. The plow members 28 are retained on the studs 21 by washers 29 and nuts. 30 that are received on reduced diameter threaded end portions of the studs. Thus the plow is mounted for vertical pivoting or turning movement on the studs 21 and horizontal tuming or pivoting movement by means of the shaft 23 in the journal member 22.

Between the forward ends of the pivoted members 28 is secured, as by bolts 3|, a plowhead 32, preferably a hard. wear-resisting steel casting. The plowhead may be of various designs, a suitable shape being as shown in the form of a saddle which is adapted to straddle the pipe being excavated. In normal position on the pipe l6 the plowhead 32 has spaced side portions 33 which extend forwardly and downwardly at an acute angle to the axis of the pipe and serve to dig or clear away the earth from along the sides and the top of the pipe as the apparatus is drawn forward. If desired, the extreme tip ends of the plowhead may be removable as shown and formed of extremely hard steel alloy such as Stellite, so that it may be replaced when worn. Furthermore an inverted U-shaped band 34, which also may be made of Stellite or similar hard alloy, is removably secured to the underside of the plowhead so as to ride along the top of the pipe l6. As shown in Fig, 5, the radius of curvature of. the plowhead 32 and associated parts is preferably greater than that of the pipe to be excavated. This arrangement provides clearances 35 between the sides of the pipe and the forward or tip end side portions 33 of the plowhead. By this arrangement radially protruding formations on the pipe, such, for example, as couplings, welds, bell ends and connecting sleeves, are first engaged by the relatively widely spaced, forwardly extending ends 33 of the plow, so that the head 32 is progressively raised over the radial obstruction on the pipe to pass over the same without injury to either the pipe or the plow. The downwardly inclined top surfaces of the plow ends 33 serve to force the end of the plow downwardly during progress of the trencher and thereby hold the plowhead firmly against the top of the pipe IS,

The excavator wheel, indicated generally at 38, is rotatably mounted between the members 1 and 8 of the boom and is provided with buckets 39 having prongs or fingers 40 which extend radially from the wheel structure across the leading edges of the buckets. These bucket teeth, fingers or prongs are of different length so that those traveling in paths beyond the sides The boom 6 carries an endless conveyor belt 4| which receives excavated earth and the like from the buckets 38 and carries the same to one side of the ditch being dug in the usua1 manner. A drive for the wheel 38 and conveyor 4| is provided and may include chain 42 having suitable connection with the engine or motor 2, in accordance with well known practice. Controls (not shown) for starting and stopping and for regulating the speed of the wheel 38 are also provided in accordance with well known practice.

An apron 43 is supported by the boom 8 and extends downwardly therefrom ahead of the uprights I0 to direct earth and other excavated material falling from the buckets forwardly into the path of the buckets at the bottom of the trench, The apron may be curved as shown to follow the path of the bucket fingers 48 and the lower end of the apron may be supported by structures 44 secured to the plate members 2! previously mentioned. If desired, adjustable apron elements 45 may be provided to vary the effective width of the apron 43. The apron elements 45 are formed with elevated slots 46 which receive bolts 41 extending through the apron 43.

An apron 48 extends upwardly and rearwardly from the plowhead 32 so that the upper end of the apron underlies the lower end of the fixed apron 43, as shown in Fig. 2. Members 48 carried by the plow side members 28 may be provided to support the upper end of the plow apron 48. A chain 58 secured to the apron 46 is received by a latch or hook 5| on the strut 44 and serves to limit the downward pivoting or turning movement of the plow on the studs 21 when the boom 6 is raised out of a ditch.

The apparatus includes an indicator which shows the direction or course of the pipe being excavated. As the plow encounters a curve or bend in the pipe, the forward or head end 32 is shifted laterally to one side or the other, depending upon the direction of the curve. This shifting of the plow imparts a turning or pivoting movement of the short shaft 23 in the journa1 member 22. The upper end of this short shaft retained in the journal member by a cap 52 and nut 53 receives telescopically the lower end of a tubular rod or pipe 54, a bolt 55 being provided to prevent turning of the pipe on the reduced diameter end of the stub shaft which receives the same. The upper end of the rod 54 is journaled in the center of a cross member 58 extending between the boom side members 1 and 8, the cross member 58 also serving as a support for the upper end of the apron 43. A lever arm 56 is secured on the upper end of the rod 54 and has secured to its end one end of a rod 51 by means of a clevis and pin, The rod 51 extends along the boom member 1, preferably between the flanges of the same, the boom members being channel shaped as shown. The other end of the rod 51 is secured to a rack 60 guided in a member 6| secured to the inside of the boom member 1.

Mounted on an upright 62 secured to the boom member 1 is a dial 63 through the center of which extends a shaft 64 journaled in the dial and a member 65 mounted on the upright 62. A pointer or finger 66 is secured on one end of the shaft 64 to move or sweep over the face of the dial 63. The other end of the shaft 64 has a beveled gear 61 that meshes with a beveled gear 68 mounted on the upper end of a shaft 63 journaled in the member 65 and the guide 6|. The

8| journaled in the upper ends of the uprights lower end of the vertical shaft 89 has a spur gear v18 secured thereon and meshed with the rack 89 so that longitudinal or endwise movement of the rack 88 induced by movement of the rod 81 rotates the shafts 88 and 84, thereby sweeping or shifting the finger or pointer 88 over the dial face. The arm 88 and gears 81, 88 and 18 are so proportioned that a very slight lateral turning or pivoting movement of the plow relative to the boom 8 produces a relatively large sweep or movement of the pointer 88 over the face of the dial 83. Accordingly, the operator who is stationed on the tractor can guide the machine to accurately follow the pipe being excavated. If the tractor should tend to leave the course of the pipe, the pointer 88 will be swung to one side or the other of a predetermined inscribed mark on the dial 83. Accordingly, the operator is immediately informed by the movement of the pointer 88 that the tratcor is moving off the course of the buried pipe and by suitable manipu- I lation of the steering controls the operator can return the tractor to the course, being guided by visual observation of the pointer 88 on the dial during such manipulation of the controls. Hence the operator, riding on the trencher or tractor, can satisfactorily steer or guide the machine without the use of markers or stakes set out ahead of the trencher to indicate the course of the pipe line.

The ends of the boom horizontal members 1 and 8 adjacent the tractor are provided with elements 1| joined by cross members 12 and pivotally connected by pins 18 to slide blocks 14. Theseblocks have fingers 15 which embrac the flanges of vertically disposed open ended I members 18 connected by top and bottom cross members 11 and 18. The cross members 11 and 18 may be of U-form or channel shaped in-cross section and the flanges thereof are received between corresponding flanges of stationary top and bottom cross members 8| and 82 secured between the uprights of the tractor frame. Vertically aligned pivot pins 83 extend through the flanges of the top pair of cross members 11 and 8| and the bottom pair of cross members 18 and 82. In this manner the open ended vertical members 18 with the cross members 11 and 18 constitute a -.pivoted frame mounted by means of the pins 83 for limited pivoting or turning movement on the frame of the vehicle or tractor.

Between the ends of each pair of cross members extend helical compression springs 84 held in position by retainers 85. Springs 84 are assembled in the structure under slight compression so as to prevent them from becoming dislodged from the retainers 85 upon turning or pivoting or vertical boom frame on the tractor frame. The springs 84 are of substantially equal strength so that the boom frame uprights 16 are normally maintained thereby in approximately equally spaced relation to the tractor frame uprights 5.

To raise and lower the boom and to tilt the same, if desired, flexible cables 86 and 81 extend from power driven drums (not shown) mounted in a suitable housing 88 and have connection with opposite ends of the horizontal members I and 8 of the boom 8. The cables 88 are trained over sheaves 89 rotatably mounted on the boom frame uprights 18 and are connected to brackets on the cross member 12 of the boom. The cables 81 are trained over sheaves 82 rotatably mounted on the tops of the uprights 5 of the tractor frame and thence around sheaves 88 mounted on a shaft l8 and above the cross members 8. The cables 81 extend from the sheaves 98 to a cushion device 8| connected to brackets 83 on the upper ends of the boom uprights 18.

The resilient spring device 9| is shown in detail in Fig. 12 and comprises end members 88 and 81 connected by parallel rods 98 that are longitudinally slidable in one or both of the end members. Extending through the center of the end member 88 and slldable therein is a rod 89 provided with an eye member I88 for connecting the same to one of the brackets 93 on the pivoted boom frame. The other end of the rod 99 has an intermediate member |||l secured thereon and slidable along the rods 98. Between the intermediate member IM and the end member 88 is disposed a helical compression spring I02 which resists movement of the intermediate member |8| toward the end member 88 due to tension in the line or cable 81. If desired, a sleeve I83 may be provided on the rod 88 to limit the movement of the intermediate member NH. The separate drums for reeling or paying out the lines 88 and 81 and mounted in the mechanism 88 are individually actuable by the engine 2, so that either end of the boom 8 may be raised or lowered at will. If desired, the horizontal members 1 and 8 of the boom with their associated parts, including the excavator wheel 38 and the plow mechanism, may be removed from the tractor by lowering the same so that the slide blocks 14 are moved below the bottom ends of the vertical members 16 of the pivoted boom frame.

By the provision of vertical pivots 83 and horizontal pivots 13, the boom structure for carrying the excavator wheel 38 and the plow mechanism can be swung about both vertical and horizontal axes so as to adapt the same to various digging or excavating conditions. Furthermore, this arrangement facilitates the steering of the tractor in following the course of the pipe line being excavated. As the pipe line curves the operator can steer the tractor without swinging the rear end of the boom so that the plow may be maintained in straddling relation. over the p pe. Furthermore, as the earth, indicated at I85, varies in depth over the pipe |6, the operator can vary the height of either one or both ends of the boom 6 so as to maintain the excavator wheel 38 in correct operative position. The cable 81 is adjusted by the operator so that the wheel l2 bears on the pipe being excavated with considerable weight, which may be less than the entire weight of the boom and related structure. Thus, the wheel l2 keeps the excavator wheel 38 in correct position relative to the pipe and operates to raise or lower the excavator wheel upon slight variations in the height of the pipe relative to the height of the surface of the ground. During up or down movement of the boom 6 under the influence of the wheel I! riding on the pipe, the tension device 9| operates to maintain the cable or line 81 taut.

The principles of the present invention may be utilized in various ways, numerous modifications and alterations being contemplated, substitution of parts and changes in construction being resorted to as desired, it being understood that the embodiment shown in the drawings and described above is given merely for purposes of explanation and illustration without intending to limit the scope of the claims to the specific details disclosed.

What I claim is:-

1.In a trencher, a vertically movable boom mounted thereon, means for supporting the boom on a pipe being excavated, and means carried by the boom and movable laterally relative to the boom, said movable means being engageable with the pipe ahead of the supporting means in the direction of travel of the trencher to indicate the directional position of the pipe relative to that of the boom.

2. In a trencher having a boom structure including an excavating wheel, support means carried by the boom for riding along a pipe being excavated, and a plow extending forwardly from said support means and formed to straddle a pipe being excavated, said plow being connected at its rear end for horizontal and vertical pivotal movement relative to the boom structure.

3. In a trencher having a boom structure including an excavating wheel, support means carried by the boom for riding along a pipe being excavated, a plow extending forwardly from said support means and formed to straddle a pipe being excavated, said plow being carried by the boom structure for relative horizontal turning movement to follow the course of the pipe, and means having connection with the plow for indicating the amount and the direction of the turning movement of the plow relative to the boom structure.

4. In a pipe line excavator having a boom structure including a rotatable excavating wheel for digging a trench, a plow carried by the boom for relative horizontal turning movement and adapted to follow the course of a pipe line being excavated, a fixed apron carried by the boom for directing earth from the top of the wheel into the path of the wheel at the bottom of the trench dug thereby, and a movable apron supported by the plow as a continuation of the fixed apron.

5. In a pipe stripping trencher, a boom structure including a rotary excavating wheel, means extending downwardly from the boom and engageable withthe pipe being excavated to support the boom on the pipe, a plow extending forwardly from adjacent the lower end of said support means to a position beneath the Wheel, and means connecting the plow to said support means for turning movement about a vertical axis,

6. In a pipe stripping trencher having excavating means and a boom structure for mounting said means, support means extending downwardly from the boom structure to adjacent the pipe, an elongated plow connected at its rear end to the lower part of the support means for pivotal side to side movement and extending forward beneath the excavating means, said plow being formed to straddle the pipe and rest upon the latter to be guided thereby during forward movement of the trencher, indicating means on the trencher positioned for observation by the operator thereof, and means connecting the plow to the indicator means to register on the latter the side to side movement of the plow.

'7. In a pipe stripping trencher having excavating means and a boom structure for mounting said means, support means extending downwardly from the boom structure to adjacent the pipe, an elongated plow connected at its rear end to the lower part of the support means for pivotal side to side movement and pivotal up and down movement, said plow being formed to straddle the 2,829,669 structure having an excavamr wheel mum]! pipe and rest thereon by gravity while the weight of theboom structure is independently carried by the support means, and apron means for directing earth falling from the upper part of the excavating means forwardly into the path of the excavating means at the lower part of the latter.

8. In a pipe stripping trencher having excavating means and a boom structure for mounting said means, support means extending downwardly from the boom structure to adjacent the pipe, an elongated plow connected at its rear end to the lower part of the support means for pivotal side to side movement and pivotal up and down movement, said plow being formed to straddle the pipe and rest thereon by gravity while the weight of the boom structure is independently carried by the support means, said connection including a shaft adapted to turn with the plow, a dial and pointer positioned for visual observation by the operator of the trencher, and rod means connecting the shaft and the pointer to move the latter over the dial in response to sideways movement of the plow.

9. In a trencher having a tractor and a boom structure including an excavator wheel, means mounting said structure on the tractor forgenerally horizontal swinging movement from side to side, and resilient means interposed between the tractor and the boom structure for yieldingly urging the boom structure to maintain a predetermined position relative to the tractor.

10. In a trencher comprising a tractor and a boom structure having an excavator wheel, a frame pivoted on the tractor for horizontal swinging movement and having spaced upright members, spaced blocks on the boom structure having sliding connection with the upright members of the pivoted frame so that the pivoted frame and the boom structure swing as a unit, and resilient means interposed between the tractor and the pivoted frame for yieldingly urging the boom structure to maintain a predetermined position relative to the tractor.

11. In a pipe stripping trencher having excavating means and a boom structure for mounting said means, support means extending downwardly from the boom structure to adjacent the pipe, and an elongated plow connected at its rear end to the lower part of the support means for pivotal side to side movement and pivotal up and down movement, said plow being formed to straddle the pipe and to rest thereon by gravity while the weight of the boom structure is independently carried by the support means,

12. In a pipe stripping trencher having a boom structure that includes a rotary digging wheel and support means extending downwardly in the rear of the wheel to ride along the pipe being stripped, a plow extending forwardly from the support means and under the digging wheel, the

plow being rearwardly connected to the support for side to side movement relative thereto in following the course of the pipe as the trencher is advanced, an upper apron secured to the boom structure and disposed behind the digging wheel to direct falling excavated material forwardly toward the bottom of the wheel, and a lower apron secured to the plow for lateral side to side movement therewith, said lower apron being dis,- posed to extend downwardly and forwardly. as a continuation of the upper apron.

JOSEPH A. SMITH. 

